Vehicle engine systems typically includes a fuel vapors control systems configured to temporarily store fuel vapors in a canister and to purge the stored fuel vapors during engine operation. Purged fuel vapors are supplied into an intake manifold of an internal combustion engine for combustion, which may lead to fuel economy as well as being environmentally friendly.
However, recent regulations impose much stricter request for effective engine performance and less environmental burden from automotive industries, and therefore further improvements on fuel vapor control systems are required.